When working with Apache web servers, inconsistent URL casing can create duplicate content issues and broken links. While some systems treat /A/B and /a/b as identical, others (particularly Windows servers) may see them as different resources. Let's implement a robust solution using mod_rewrite.

This rule checks for uppercase letters in the URL path and redirects to lowercase:

RewriteEngine On
RewriteMap lowercase int:tolower
RewriteCond %{REQUEST_URI} [A-Z]
RewriteRule ^(.*)$ ${lowercase:$1} [R=301,L]

The solution uses three key Apache modules:

• mod_rewrite: For URL rewriting capabilities
• mod_map: For the lowercase conversion function
• mod_alias: For the redirect functionality

For more control, you can modify the rule to exclude certain paths or file extensions:

RewriteEngine On
RewriteMap lowercase int:tolower
RewriteCond %{REQUEST_URI} [A-Z]
RewriteCond %{REQUEST_URI} !^/exclude [NC]
RewriteCond %{REQUEST_URI} !\.(jpg|png|gif)$ [NC]
RewriteRule ^(.*)$ ${lowercase:$1} [R=301,L]

After implementing the rules:

1. Clear your browser cache
2. Test with various URL cases (/TEST/Page, /Test/Page)
3. Verify the 301 redirect occurs
4. Check server logs for rewrite processing

The rewrite map approach is generally efficient, but for high-traffic sites:

• Place the rule early in your .htaccess file
• Consider adding caching headers
• Monitor server load after implementation

When dealing with web applications, URL case sensitivity can create duplicate content issues and broken links. Apache servers treat /A/B and /a/b as different resources by default, which isn't ideal for most applications.

Here's a complete solution that redirects uppercase URLs to their lowercase equivalents while preserving query strings:

RewriteEngine On
RewriteMap lowercase int:tolower
RewriteCond %{REQUEST_URI} [A-Z]
RewriteRule ^(.*)$ ${lowercase:$1} [R=301,L]

This configuration:

• Activates Apache's rewrite engine
• Creates a lowercase conversion map
• Checks for uppercase characters in the URI
• Performs a 301 redirect to the lowercase version

For more complex scenarios including query strings:

RewriteEngine On
RewriteMap lowercase int:tolower
RewriteCond %{REQUEST_URI} [A-Z]
RewriteRule ^(.*)$ ${lowercase:$1} [R=301,L,QSA]

The QSA flag ensures any query parameters (?param=value) are preserved during the redirect.

When implementing this solution:

• Use 301 (permanent) redirects for SEO benefits
• Place these rules near the top of your .htaccess file
• Test thoroughly in development before production deployment
• Consider combining with other URL normalization rules

If the redirect isn't working:

1. Verify mod_rewrite is enabled in Apache
2. Check for syntax errors in .htaccess
3. Ensure the rules are in the correct order
4. Test with different browser sessions (clear cache)

# Debugging tip: Add this to check rewrite processing
RewriteLog "/var/log/apache2/rewrite.log"
RewriteLogLevel 3